I need a clear explanation of how pict files created by powercad are imported into DW.
If the powercad file is set to 1/4 inch scale and drawn with GRID snaps on (say 4 inch snaps) and a 4 foot by 4 foot rectangle is imported into DW the pict image has to be scaled by 4800% right? if drawn at 1/8 scale it would be 9600%?. Anyway, if I scale the pict image by 4800% the info box in DW should say 4 foot by 4 foot (if units are set to feet or 48 x 48 if set to inches) but in reality I get an odd dimension like 3 feet 11.8 or something like that. And if I set the grid snap in DW to 4 inch increments, the cursor should snap right on the rectangle lines (since it was created on 4 inch increments) but it NEVER does; it is always a little off. If i move the image to align one edge with the DW grid, and i move the cursor to snap to grid, the other edge is off.
I've always just disregarded this discrepancy and just recreated a new geometry "kind of" tracing the imported PICt image but I run more and more into situations where the drafting HAS to be done in Powercad for different "parts" due to the drafting limitations of DW so the "approximate" tracing does not work anymore.
IS there a fullproof way to avoid this? ie bring the PC drawing accurately into DW?
Do some scale factors in PC work better than others? does it have to do with the "accuracy" setting in PC?

I believe that the behavior you're describing is something intrinsic to the PICT file format. So, while PowerCADD and DW are both exceptionally accurate design tools, the data you move between the two is only as good as the file format you're using.

In general, I tend to use DXF files when transferring data in either direction. DXF certainly has its own quirks, but the question of dimensional consistency is not usually an issue. If there is a scaling discrepancy, the solution is typically something simple like scaling by 1200% (to convert from inches to feet) or by 8.33333% (to go the other direction).

If you create polylines in PowerCADD, you should be able to extrude those directly into 3D once they're in DesignWorkshop, with little or no tracing needed.

PowerCADD has a couple of great commands that I use routinely when making complex polygonal forms from simpler constituent shapes:

Tool, Convert to Lines - converts curves and other complex shapes into a series of line segments. Use the "Tool, Convert to Lines..." dialog box to select the conversion accuracy from three presets: Low, Medium, High.

Tool, Attach - combines a series of line segments into a single polygonal shape.

And a word on polylines. I'd recommend creating open polylines in PowerCADD (where the two end points of the polyline are not in the same place) rather than closed polylines. DesignWorkshop will automatically close the polylines when you're extruding them by drawing a straight line between the two endpoints. And in general, I find I get better results this way.

I HAVE TRIED THE DXF ROUTE. But I get the same results. It comes at a weird scale and have to spend lots of time by trail and error with what scaling factor to use. I WANT TO KNOW HOW DW RECEIVES THE DATA. Say if the drawing is at 1"=60' in PC and I export (save as) to DXF it would seem that it should come in at 1 to 1 OR at the 1/60th ratio but it does NOT. There has to be a consistent way DW reads the incoming data right?

DesignWorkshop always reads DXF file units in inches. If you're working in unit feet in PowerCADD, then you'll need to scale up by 12 times (1200%). If you're working in centimeters, then the scaling factor is 0.3937 (39.37%).

If you set PowerCADD to work in units of inches (for example, right before you save the DXF file), then you'll get the direct 1 to 1 that you're looking for. No rescaling required.